Education

Lactobacillus casei

Lactobacillus casei is a species in the genus Lactobacillus encompassing most of the lactic acid bacteria in our body. It has all kinds of health benefits. Lactic acid bacteria convert lactose (milk sugar) into lactic acid – that’s what gives them their name. As well as doing this in our body, they also do it in certain foods, such as cheddar cheese and Sicilian green olives. L. casei is therefore highly useful in the food industry.

Latin name

Lactobacillus casei

Size

2-4 µm long

Habitat

mouth, intestines and in some fermented foods

Domain

Bacteria

Lactobacillus casei is a species in the genus Lactobacillus encompassing most of the lactic acid bacteria in our body. It has all kinds of health benefits. Lactic acid bacteria convert lactose (milk sugar) into lactic acid – that’s what gives them their name. As well as doing this in our body, they also do it in certain foods, such as cheddar cheese and Sicilian green olives. L. casei is therefore highly useful in the food industry.

With or without oxygen

Lactobacillus casei is found in different parts of the body, especially in the mouth and intestines. It therefore has a high tolerance for pH (acidity) and a wide range of temperatures. But pH and temperature are not the only differences between mouth and intestines. The biggest difference is the lack of oxygen in the intestines (​anaerobic), while the mouth is full of oxygen (​aerobic). L. casei is a facultative anaerobic organism, meaning that it can survive with or without oxygen. This is useful, since L. casei has all kinds of essential tasks in the anaerobic intestines.

Extra resistance

One thing L. casei does is regulate the immune system of the intestines. The bacteria attach to the intestinal wall where they stimulate the intestinal lymph tissue that reinforces the body’s immune response. L. casei also protects the body against ​pathogens by competing with them for food and space. In addition, the bacteria reduce the growth of pathogens by lowering the pH with the acids they produce. They also make bacteriocins: antimicrobial proteins which kill pathogens.

Slightly sweet

Besides the key role L. casei plays in our intestines, in the mouth L. casei complements the growth of another lactic acid bacteria, L. acidophilus, which produces the ​enzyme amylase. This forms part of our saliva and ensures that starch is converted into sugars. This is why food which contains a lot of starch but few sugars, like rice or potatoes, sometimes tastes slightly sweet when you chew it.

Probiotics

Because L. casei is so important to health it is often used as a probiotic.
Probiotics
are microbes which can have a beneficial effect on health if ingested in sufficient amounts. Research shows, for example, that as a probiotic L. casei can reduce the chance of intestinal infection and improve bowel movement.